A patient-specific numerical model of the ankle joint for the analysis of contact pressure distribution

Abstract

A patient-specific numerical model of the ankle joint has been developed using open-source software with realistic material properties that mimics the physiological movement of the foot during the stance phase of the gait cycle. The patient-specific ankle geometry has been segmented as a castellated surface using 3DSlicer from the computed tomography image scans of a subject with no congenital or acquired pathology; subsequently, the bones are smoothed, and cartilage is included as a uniform thickness extruded layer. A high-resolution Cartesian mesh has been generated using cfMesh. The material properties are assigned in the model based on the CT image Hounsfield intensities and compared to a sandwich-based material model. Gait data of the same subject was obtained and used to relatively position the tibia, talus, and calcaneus bones in the model. The stance phase of the gait cycle is simulated using a cell-centred finite-volume method implemented in open-source software OpenFOAM. The predicted peak contact pressures occur in the range of 4.85–5.53 MPa with average pressures in the range of 1.56–1.95 MPa, and the contact area ranges between 429 and 707.8 mm2 for the entire stance phase with the mid-stance phase predicting the maximum contact area. These predictions are in agreement with results from the literature. The effect of arthritis on the contact characteristics of the ankle joint has also been examined. A concentrated increase in pressure was predicted that could be manifested as pain, thereby leading to reduced motion in the ankle. The model, with continued development, has the capability to understand the effect of joint degradation and furthermore, could help provide a tool to predict the efficiency of therapeutic surgical procedures as well as guide the development of next generation ankle prostheses. The work would be made available in the University College Dublin depository ( https://github.com/laxmimurali/anklejoint ) as well as research gate once the article has been published.

Total ankle replacement along with subtalar joint arthrodesis: In‐vitro and in‐silico biomechanical investigations

“…Thus, STJ fusion, based on the results of this work, along with using TAR prosthesis, reduces the chance of prosthesis failure, and also can likely improve endurance of the TAR prosthesis. The maximum contact stresses in the tibial plateau was found to be 4 MPa in this study (Figure 6) which is in a good agreement with the experimental studies in the literature 3,29,35 …”

“…The maximum contact stresses in the tibial plateau was found to be 4 MPa in this study (Figure 6) which is in a good agreement with the experimental studies in the literature. 3,29,35 The FE models of TAR and FTAR cases could replicate the respective experimental data with a reasonable tolerance (Table 2). Also, the obtained range for the vM stresses in bone and prosthesis is in agreement with previous reports.…”

“…Synovial joints of lower extremity, especially the ankle joint, experience substantial loads during daily activities 1–3 . Presence of many adjoining bone, their irregular shapes and articulating surfaces make ankle prone to traumatic injuries 4–6 .…”

“…Synovial joints of lower extremity, especially the ankle joint, experience substantial loads during daily activities. [1][2][3] Presence of many adjoining bone, their irregular shapes and articulating surfaces make ankle prone to traumatic injuries. [4][5][6] Post-traumatic ankle arthritis, resulting from impact or collision, is much more prevalent than other problems in lower extremity joints.…”

Finite Element Analysis of Normal and Dysplastic Hip Joints in Children

“…Autodesk Inventor software version 2022 was used to conduct finite element analysis on the two hips. In the process of generating meshes for the cortical, trabecular bone, and cartilage, we employed linear solid hexahedral elements, as depicted in Figure 2 [20,21]. In the normal hip model, 29,907 hexahedral elements and 55,627 nodes were used.…”